Search Publications
First Detection of HCO+ Absorption in the Magellanic System
Murray, Claire E.; Stanimirović, Snežana; Wong, Tony +9 more
We present the first detection of HCO+ absorption in the Magellanic System. Using the ATCA, we observed nine extragalactic radio continuum sources behind the Magellanic System and detected HCO+ absorption toward one source located behind the leading edge of the Magellanic Bridge. The detection is located at an LSR velocity of…
Origin of the Diffuse, Far Ultraviolet Emission in the Interarm Regions of M101
Calzetti, Daniela; Leitherer, Claus; Chandar, Rupali +4 more
We present images from the Solar Blind Channel on the Hubble Space Telescope that resolve hundreds of far-ultraviolet (FUV) emitting stars in two ∼1 kpc2 interarm regions of the grand-design spiral M101. The luminosity functions of these stars are compared with predicted distributions from simple star formation histories, and are best r…
The VMC Survey. XVIII. Radial Dependence of the Low-mass, 0.55--0.82 M Stellar Mass Function in the Galactic Globular Cluster 47 Tucanae
Piatti, Andrés E.; Deng, Licai; de Grijs, Richard +12 more
We use near-infrared observations obtained as part of the Visible and Infrared Survey Telescope for Astronomy (VISTA) Survey of the Magellanic Clouds (VMC), as well as two complementary Hubble Space Telescope (HST) data sets, to study the luminosity and mass functions (MFs) as a function of clustercentric radius of the main-sequence stars in the G…
COLDz: Karl G. Jansky Very Large Array Discovery of a Gas-rich Galaxy in COSMOS
Smail, I.; Daddi, E.; Ivison, R. J. +15 more
The broad spectral bandwidth at millimeter and centimeter wavelengths provided by the recent upgrades to the Karl G. Jansky Very Large Array (VLA) has made it possible to conduct unbiased searches for molecular CO line emission at redshifts, z > 1.31. We present the discovery of a gas-rich, star-forming galaxy at z = 2.48 through the detection …
An Extreme Gravitationally Redshifted Iron Line at 4.8 keV in Mrk 876
Greiner, Jochen; Ajello, Marco; Bottacini, Eugenio +3 more
X-ray spectral lines at unforeseen energies are important because they can shed light on the extreme physical conditions of the environment around the supermassive black holes of active galactic nuclei (AGNs). Mrk 876 displays such a line at 4.80+0.05-0.04 rest-frame energy. A possible interpretation of its origin can be foun…
A Chandra Observation of the Eclipsing Wolf-Rayet Binary CQ Cep
Skinner, Stephen L.; Zhekov, Svetozar A.; Güdel, Manuel +1 more
The short-period (1.64 d) near-contact eclipsing WN6+O9 binary system CQ Cep provides an ideal laboratory for testing the predictions of X-ray colliding wind shock theory at close separation where the winds may not have reached terminal speeds before colliding. We present results of a Chandra X-ray observation of CQ Cep spanning ~1 day during whic…
LBT/LUCI Spectroscopic Observations of z≃7 Galaxies
Fan, Xiaohui; Jiang, Linhua; McGreer, Ian D. +7 more
We present deep near-infrared spectroscopic observations of 13 luminous z≃ 7 Lyman break galaxies (LBGs) ({{M}UV}≃ -21) and a z≃ 9.6 lensed LBG candidate, MACS1149-JD1, using the LBT/LUCI spectrograph in the multi-object mode and long-slit mode, respectively. The z∼ 7 galaxies are selected in one of the Cosmic Assembly Near-infrared Dee…
Probing the Solar Wind Acceleration Region with the Sun-grazing Comet C/2002 S2
Lamy, P.; Raymond, J. C.; Dobrzycka, D. +2 more
Comet C/2002 S2, a member of the Kreutz family of sungrazing comets, was discovered in white-light images of the Large Angle and Spectromeric Coronagraph Experiment coronagraph on the Solar and Heliospheric Observatory (SOHO) on 2002 September 18 and observed in H I Lyα emission by the SOHO Ultraviolet Coronagraph Spectrometer (UVCS) instrument at…
A Detection of Gas Associated with the M31 Stellar Stream
Danforth, Charles W.; Rich, R. Michael; Keeney, Brian A. +2 more
Detailed studies of stellar populations in the halos of the Milky Way and the Andromeda (M31) galaxies have shown increasing numbers of tidal streams and dwarf galaxies, attesting to a complicated and on-going process of hierarchical structure formation. The most prominent feature in the halo of M31 is the Giant Stellar Stream, a structure ∼4.°5 i…
A Luminous X-Ray Flare from the Nucleus of the Dormant Bulgeless Spiral Galaxy NGC 247
Tao, Lian; Feng, Hua; Grisé, Fabien +4 more
NGC 247 is a nearby late-type bulgeless spiral galaxy that contains an inactive nucleus. We report a serendipitous discovery of an X-ray flare from the galaxy center with a luminosity of up to 2× {10}39 erg s-1 in the 0.3-10 keV band with XMM-Newton. A Chandra observation confirms that the new X-ray source is spatially coinci…